Apparatus for filling a pipeline to be hydrostatically tested



United States Patent Inventors Appl. No.

Filed Patented Assignee Phil E. Moore Fort Madison, Iowa;

Carl G. Danielson, Houston, Texas Feb. 6, 1968 Oct. 13, 1970 said Moore assignor to Philley Brush Company a corporation of Iowa APPARATUS FOR FILLING A PIPELINE TO BE HYDROSTATICALLY TESTED 5 Claims, 14 Drawing Figs.

US. Cl .l 137/802 73/405 Int. Cl G0lm 3/08 Field of Search l 37/802,

References Cited UNITED STATES PATENTS 953,666 3/l9l0 Inglee 15/104.06 2,188,959 Z/l 940 Schaer 15/l04.06 2,953,800 9/1960 Bowerman l37/802UX 3,237,594 3/1966 Weaver et al l5/l04.06UX

Primary E.taminer-M. Cary Nelson Assistant Examiner-Michael O. Sturm Atmrney- Henderson and Strom ABSTRACT: This invention relates to an apparatus for hydrostatically filling a pipe line to be hydrostatically tested; the apparatus comprising a slotted cylinder with discs of greater diameter at each end, the disc diameter being substantially that of the pipe line, and each end of the cylinder closed by a head having a plurality of one way, low pressure valves set therein to allow fluid to flow into the cylinder onlyv I Patented Oct. 13, 1970 Sheet APPARATUS FOR FILLING A PIPELINE TO BE IIYDROSTATICALLY TESTED BACKGROUND OF THE INVENTION This invention relates to a novel apparatus for use in hydrostatically testing a section of pipe line for leakage.

The test involves generally filling the pipe with water and adding pressure, sealing the pipe for a period of time and noting any change in pressure in the sealed pipe. In order to make the test it is essential that substantially all the gas within the pipe is expelled and replaced by water.

Though hydrostatic testing for leakage in a pipe line is the simplest and most economical way to test a pipe, other tests have been devised because of the heretofore inability to completely evacuate the gas simply from the pipe, thus leading to erroneous tests. The apparatus of this invention removes the gas so substantially that accurate tests may now be assured.

The prior art in this field is relatively void, showing only US. Pat. Nos. 2,705,419 and 2,258,174 referred to therein. The disadvantage of this device is the necessity of using a plurality of devices and adding a plurality of modifications to the pipe to adapt the device to its purpose, thereby complicating the test and increasing the time of the operator or tester.

SUMMARY OF THE INVENTION This invention relates to an apparatus to be inserted into a pipe to be hydrostatically tested, the apparatus being driven through the pipe by water entering the pipe at the rear of the apparatus and pushing the gas enclosed within the pipe ahead of it, the apparatus having a slotted cylindrical body sealed at its longitudinal ends, flexible rings secured at each end of the body and extending radially outward therefrom to contact the inside wall of the pipe and thereby forming a seal, and one or more one-way valves attached to the sealed ends of the body, the valves opening inwardly to the body in response to an increase of pressure without the body. By this arrangement, the fluid pushing the apparatus exerts a force against the leading set of rings whereby the apparatus will not tend to become cocked in the pipe line, which if occurs creates problems.

It is an object of this invention to provide a novel apparatus for use in hydrostatically testing a section of pipe line for leakage.

It is another object of this invention to provide an apparatus insertable in a pipe to be hydrostatically tested which is movable longitudinally through the pipe by the pressure of fluid entering the pipe behind it, and with the fluid exerting the same pressure against its leading end as against its trailing end.

It is another object of this invention to provide an apparatus insertable in a pipe which in conjunction with the walls of the pipe will seal the pipe under ordinary pressure.

It is yet another object of this invention to provide an apparatus which will effectively remove substantially all gaseous matter from a pipe to be hydrostatically tested.

It is still another object of this invention to provide an apparatus for use in hydrostatically testing a pipe line which is capable of withstanding the pressure within the pipe and which may remain within the pipe throughout the test.

It is another object of this invention to provide an apparatus for use in hydrostatically testing a pipe line which will effectively remove the test fluid from the pipe following the test without removal or turning around of the apparatus.

It is another object of this invention to provide a light weight portable apparatus to be inserted into a pipe line for hydrostatically testing the pipe.

It is a further object of this invention to provide an apparatus capable of attaining the above designated objectives which is economical to manufacture, simple and rugged in structure, and effective in operation.

These objects and other features and advantages of this invention will become readily apparent upon reference to the following description, when taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic, fragmentary view of the apparatus of this invention in assembled relation with a pipeline, and showing in broken lines the apparatus in test position;

FIG. 2 is an enlarged side elevational view of the apparatus of this invention;

FIG. 3 is an elevational view as taken along the line 33 of FIG. 2;

FIG. 4 is a sectional view as taken along the line 4-4 of FIG. 2, and showing the apparatus within a section ofthe pipeline;

FIG. 5 is a sectional view as taken along the line 5-5 of FIG.

FIG. 6 is an enlarged sectional view of one of the valves in an end of the body of the apparatus;

FIG. 7 is an enlarged fragmentary, sectional view showing the attachment of a set of flexible rings to the body of the apparatus;

FIG. 8 is a side elevational view of a modification of the apparatus of this invention;

FIG. 9 is an elevational view as taken along the line 9-9 of FIG. 8;

FIG. 10 is a sectional view as taken along the line 10-10 of FIG. 8;

FIG. 11 is a sectional view as taken along the line 11-11 of FIG. 8;

FIG. 12 is an enlarged sectional view of a control valve of the modification of this invention;

FIG. 13 is an enlarged sectional view of a detail of the modification;

FIG. 14 is a sectional view as seen along the line 14-14 of FIG..12.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings and particularly FIG. 1, the

apparatus of this invention is indicated generally at 20 and is shown in assembled relation with a pipe line 21. I

The pipe line 21 is a conventional cylindrical tube or pipe of steel or like material and is sealed at one end 22 by a header or bull-plug attached to the pipe 21 as by welding. Integral with the bull-plug 23 is a conduit or inlet 24 fluidly connecting the sealed section 26 of pipe line 21 to a water source for purposes of the test. Fluidly connecting the inlet 24 is a high capacity water pump P used to fill the test section 26 of the pipe line 21 with water under an elevated pressure, and a pressure gauge 27 to record the inlet 24 water pressure.

An outlet or drain line 28 and and valve 25 therein is likewise fluidly connected to the bull-plug 23 to provide for removal of the water within the test section 26 of the pipe line 21 following the test. A third conduit 29 described as a dead weight test line fluidly connects the bull-plug 23 to an extremely sensitive gauge 30 and functions as a conduit for recording the internal pressure within the test section 26 of the pipe line 21 during the test period when the pipe 26 is completely sealed.

Separating the test section 26 from the remainder 31 of the pipe line 21 is a main valve 32. The main valve 32 is comprised of a relief mechanism in the form of a conduit 35 and valve 40 therefor, which after closure of the section 26 to be tested from the remainder 31 of the pipe line 21, provides for an escape for trapped air or gas within the section 26 to the atmosphere as the apparatus 20 moves toward the valve 32 as hereinafter described. In certain instances, another bull-plugidentical to plug 23 could be placed on the side of the main valve 32 next to the section 26 to seal off that end, and with the main valve 32 in fluid communication with the sealed end.

The apparatus 20 of this invention consists generally of a cylindrical body 33 (FIG. 2) attached to a set of flexible rings 34 at each end, and with a plurality of valves 36 fluidly connecting the chamber 37 (FIG. 1) of the pipe 26 to the interior 40 (FIG. 4) of the body 33 of the apparatus 20.

Specifically, the body 33 (FIG. 2) of the apparatus 20 is an elongated cylinder sealed at its longitudinal ends by tank heads 38, 38', and adapted for insertion into a pipe line 21.

The body 33 is of steel or like material and is provided with a plurality of slots 39 spaced about the periphery of the cylinder 33 to fluidly connect the area 41 (FIG. 1) defined by the pipe line wall 42, the interior of the cylinder 33, and between the sets of rings 34.

The tank heads 38, 38' are identical and therefore only one tank head 38 will be described. The tank head 38 (FIG. 4) is a dome shaped member projecting axially from its outer surface to form a union 43 with the cylinder wall 33. The head 38 is of similar material as the cylinder 33 and is sealed as by welding to the cylinder 33. The tank head 38 has a plurality of radially spaced apertures 44 formed therein as best illustrated in FIG. 6. Secured within each aperture 44 is a tube 47. The tubes 47 extend parallel to each other and parallel to the longitudinal axis of the cylinder 33, and each tube is provided with an inner end 47 of lesser diameter than the tube 47. A commercially available valve 36 (FIG. 6) is threadably inserted into each tube end 47, extending inwardly from the tank head 38 or 38' in a countersunk manner.

Each valve 36 comprises a housing 62 having a bore 63 formed therein, with a shoulder 64 intermediate the ends of the housing 62, and with a valve seat 66 at the innermost end of the housing. Within the housing 62 is secured a valve 67 by means of the shoulder 64, which valve includes a plunger 68 biased away from the valve seat 66 by means of a coil spring 69.

As indicated in FIG. 6, the valve 67 is normally positioned such that fluid entering the outer end of the housing 62 may pass through the bore 63 and around the plunger 68, internally of the filling body 33 (FIG. 4). Should fluid, conversely, attempt to move through the valve assembly 36 from left to right as viewed in FIG. 6, the plunger 68 would be forced against the valve seat 66, thereby closing the valve 36 assembly against the passage of fluid therethrough. Referring to FIG. 4, it is noted that the valve assemblies 36 mounted in the left end head 38 permit fluid to enter the cylinder 33 from outside thereof, but prevent fluid from leaving the cylinder 33 by that route; whereas the valve assemblies 36 mounted in the right end head 38, mounted oppositely of the left end valve assemblies 36, permit fluid to enter the cylinder 33 from right to left, but prevent the opposite flow.

To mount each set of rings 34, a plate 48 (FIGS. 4 and 7) is welded at 49 to the cylinder body 33 on an inner side of a welded union 43 formed between the body 33 and the head 38 so as to be positioned about the periphery of the cylinder 33 at each end thereof. Each ring 48 is provided with a plurality of apertures 51 radially spaced about the ring 48.

Each set of rings 34 is comprised of a plurality of identical flexible rings indicated by 34 plus a prime (FIG. 7), the rings being mounted in juxtaposed relation to each other and embracing the body 33 of the apparatus in a fluid tight manner. The inner diameter 57 (FIG. 7) of each ring is slightly larger than the outer diameter 57 of the cylinder 33 to facilitate the encirclement of the rings within each set 34 about the cylinder. The first ring 34 overlaps the cylinder 33 and is positioned contiguous to the welded plate 48; a second ring 34" is added in the same manner and positioned adjacent ring 34', and with a third ring 34" forming the outside. A number of rings in a set 34 is not meant to be critical, but only sufficient to form a fluid tight seal between each end of the cylinder 33 and the pipe line section 26.

Each ring is provided with a plurality of apertures 59 (FIG. 7) for alignment with each other and with the apertures 51 of the inner plate 48. The outer diameter 61 of each ring of a set 34 is approximately the same as the inner diameter of the pipe section 26 to be tested so as to be contiguous with the inside wall thereof to form a fluid tight seal, under ordinary pressure, when the apparatus 20 is inserted into the pipe section 26 (FIG. 1).

A second plate 52 (FIGS. 2 and 7), similar to the first plate 48, and having radially spaced apertures 53 (FIG. 3) formed therein is adapted to connect a set of rings 34 to the first plate 48 at each end of the cylinder 33 by a plurality of nuts 54 and bolts 56 inserted through the aligned apertures 51, 59, and 53. Unlike the first rings 48, the outermost rings 52 are not welded to the cylinder 33 but are detachably connected to the ring sets 34.

In the operation of the present invention, the section 26 (FIG. I) of the pipe line 2] to be hydrostatically tested is closed off at each end by the plug 23 at one end and a main valve 32 at the other end, or as mentioned hereinbefore with an additional plug (not shown) at the right end of the section 26 as viewed in FIG. 1, and with the additional plug in fluid communication with the valve 32 and the associated elements described hereinbefore.

The apparatus 20, having been inserted into the left end of the pipe section 26 prior to the sealing thereof is placed under the pressure of a fluid introduced into the section 26 on the left end of the apparatus 20 as viewed in FIG. 1, by means of operation of the high capacity pump P forcing fluid through the conduit 24 and into the pipe section 26. At this stage of the proceedings, the main valve 32 and the relief valve 40 are both cracked such that the conduit 35 is open to the atmosphere, wherein as the apparatus 20 is moved from left to right within the pipe section 26 as viewed in FIG. 1, the fluid within the pipe section 26 on the right side of the apparatus 20 is forced outwardly through the conduit 35 to the atmosphere.

Referring now to FIG. 4, fluid entering the pipe line section 26 is indicated by arrows moving from left to right in the illustration, and due to the action of the valve assemblies 36 mounted within the tubes 47, the fluid, such as water, passes through those valve assemblies 36 and as indicated by arrows enters the interior 40 of the cylinder 337 As the interior 40 fills up, the water is then allowed to emit therefrom through the slots 39 such that it escapes into the annular space between the exterior of the cylinder 33, the interior of the pipe line section 26, and with the annular space defined longitudinally by the two sets of flexible rings 34.

As this annular space, indicated by the reference numeral 96 in FIGS. 1 and 4, is filled, the fluid will then impinge upon the inner surface 97 of the innermost ring 34' of the set 34 of rings at the right end of the cylinder 33, again as indicated by arrows in FIG. 4. It will be noted that the fluid within the cylinder 33 can not pass from left to right, as viewed in FIG. 4, through the valve assemblies 36 mounted in the right end head 38' due to the opposed arrangement of the valve assemblies 36 as defined hereinbefore.

As more water is pumped into the pipe line section 26 against the left end of the apparatus 20 as viewed in FIG. 1, the apparatus 20 will move from left to right and down the pipe line section 26, removing all air or other fluid within the section 26 through the conduit 35 as the apparatus moves to the end of the section 26 to be tested.

The apparatus 20, when moving through the pipe line section 26, takes advantage of the buoyancy of the fluid about it, and therefore moves through the pipe line section 26 with less resistance because it is actually being pulled through the section 26 by the pressure exerted on the front or leading set 34 of rings. Furthermore, due to this arrangement the apparatus will not tend to become cocked in the pipe line section 26, which cocking would create a greater resistance to movement of the apparatus 20, and greater wear on the flexible rings of the sets 34.

When the apparatus has reached the end of the pipe line section 26 to be tested, as indicated by the dotted line apparatus 20 at the right end of the section 26 in FIG. 1, and the section 26 is completely filled with fluid, the pressure of the fluid is still increased to a point where the fluid will pass over the periphery of the rings of the leading set 34 and in front of the entire apparatus 20, allowing the apparatus then to become completely surrounded. The fluid pressure is still further increased by operation of the water pump P to that required for the hydrostatic test, and is held at this pressure for the required length of time. It should be noted, that prior to increasing the pressure within the line, after the apparatus 20 is at the right hand end of the section 26, the main valve 32 and the relief valve 40 were closed to permit the pressure to be increased to that required for the hydrostatic test. During the hydrostatic test, the gauge 30 and the dead weight test line is utilized to record and indicate the results of the hydrostatic test.

When the test is completed, the valve (FIG. I) in the relief conduit 28 is cracked, and fluid such as gas or air is in troduced into the right end of the section 26 through the conduit 35 and the main valve 32. When this pressure on the right end of the apparatus 20 overcomes the capacity of the valve assemblies 36 mounted in the head 38', they will open against the pressure of the fluid within the apparatus 20 and the annular chamber 96, removing the water from in front of the apparatus 20, and by the same exact arrangement as described before with respect to the water entering the left end of the apparatus 20, the gas or air pressure now entering the right end of the apparatus 20 will force all water out of the cylinder 30 and the annular chamber 96 such that the air or gas pressure will then impinge upon the set of rings 34 at the left end of the apparatus 20 as viewed in FIG. 4, whereby that set of rings 34 becomes the leading set of rings and again the apparatus 20 is not pushed to the left through the section 26 to clear the water therefrom, but is literally pulled therethrough in the same manner as the apparatus 20 was pulled" from left to right in the section 26. When the apparatus 20 has been pulled to the left end of the section 26 as illustrated in FIG. 1, with all fluid removed thereby, the fluid removal being effected in the same manner as the air or gas was removed as described hereinbefore, the gas or air pressure to the right side of the apparatus 20 is then relieved back through the main valve 32 and the relief valve 40, removing the pressure within the pipe line section 26 whereby the plug 23 may be removed, the apparatus 20 removed, and the pipe line 21 then rescaled for subsequent use.

Referring now to FIGS. 8 through 14 inclusive, a modification of the apparatus 20 is indicated generally at 20'. All like elements are referred to by like reference numerals as to the first embodiment of FIGS. 1-7 inclusive. It is noted that the cylindrical body 33 is the same with the slots 39 formed therein, and also a pair of sets 34 of flexible rings of identical construction are again mounted at opposite ends of the body 33. An additional ring has been added to each set, such that each set is comprised of four rings instead of three, but as mentioned hereinbefore this is not critical.

The main difference between the embodiment 20' and the initial embodiment 20 is in the removal of the oppositely mounted valve assemblies 36 from the cylinder heads 38 and 38', with the substitution of a single slide valve assembly indicated generally at 71 in FIG. 10. This slide valve assembly 71 comprises basically an elongated tube 72 extended completely through the cylinder 33, a pair of cap devices 73 and 74 mounted on opposite ends of the tube 72, and a slide valve 76 slidably mounted within the tube 72 for reciprocal movement therein.

Specifically, the tube 72 has a plurality of arcuately arranged slots 77 formed at its mid-point therein, and has a pair of internally threaded collars 78 secured to the externally formed threads of the tube 72 at each end thereof.

The cap devices 73 and 74 are identical, with only one illustrated best in FIG. 13 being described. This cap device 74 includes an annular stop member 79 mounted within the collar 78, as by welding, and with a semicircularly curved element 81 welded to the end of the collar 78 such that fluid may enter the end of the tube 72 from the sides of the element 81.

The slide valve 76 is best illustrated in FIGS. 12 and 14, and comprises a short rod 82 adapted to be mounted axially within the tube 72 by means of a pair of flexible discs 86 and 87 secured at each end thereof against an inner plate 88 which is welded to each end of the rod 82. A pair of nuts 89 and 91, and washers 92 and 93 are mounted on and threaded to the threaded ends 83 and 84 of the rod 82 so as to retain the pairs of discs 86 and 87 in place.

The outer diameter of the discs 86 and 87 is such that a frictional sliding engagement is made with the inner surface of the tube 72. As the slide valve 76 approaches each end of the tube 72, it will be noted that the stop member 79 forms an annular shoulder against which the outer disc 86 in one instance, and 87 in the other instance, of the slide valve 76 will engage. As the stop member 79 is welded to the collar 78, further movement of the slide valve 76 away from the mid-point of the tube 72 is thereby prevented.

In operation of the modified apparatus 20', the entire system'as depicted in FIG. 1 is identical, with the only change being in the operation of the apparatus 20' itself.

With the slide valve 76 in the position illustrated in FIG. 1Q. as water enters the pipe line section 26 to the left of the apparatus 20', as indicated by the arrows, the fluid will impinge upon the left face of the set 34 of rings, but it will also enter through the exposed, open end of the tube 72 into the left end of the tube 72. As the capacity and pressure of the water increases, it will impinge upon the left end of the slide valve 76 (FIG. 12), again as illustrated by arrows. This will force the slide valve 76 from its left position in the tube 72 toward the right, and as the slide valve 76 passes to the right beyond the slots 77 formed in the tube 72, water will enter the interior 40 of the cylinder 33. 1

Additional capacity and pressure of the water within the pipe line section 26 will continue to cause flow of water within the cylinder 33 (FIG. 10) to then flow outwardly of the slots 39 and into the annular chamber 96 formed between the exterior of the cylinder 33, the interior of the section 26 at that point, and between the ring sets 34. Increased pressure will then impinge the water against the inner face 97 (FIG. 10) of the leading set 34 of rings, as indicated by arrows, whereby the apparatus 20 will move from left to right within the pipe line section 26 in exactly the same manner, and with exactly the same function as the initial apparatus 20, described hereinbefore. During this time, the increased pressure of the water will have forced the slide valve 76 to the end of the tube 72 and against the stop member 79 (FIG. 13) at the right end thereof as viewed in FIG. 13. It will be noticed that in this position of the slide valve 76, water within the cylinder chamber 40 can not pass outwardly and to the right thereof through the tube 72, due to the fluid tight seal of the slide valve 76 with the stop member 79.

It is not believed necessary to describe completely the reverse or opposite movement of the modified apparatus 20 within the section 26, as again the operation of the system as depicted and described in FIG. 1 with respect to the modified apparatus 20' is exactly like that of the apparatus 20. Suffice it to say, that the slide valve 76 is moved from right to left within the tube 72 as viewed in FIG. 10, and with the gas or air pressure exiting the water from the annular chamber 96 and the interior 40 of the cylinder 33 to the extent that the gas or air pressure impinges upon the inner surface of the left set 34 of rings, as viewed in FIG. 10, and again wherein the apparatus 20 is not pushed, but pulled from right to left within the section 26 which has been hydrostatically tested.

We claim:

1. An apparatus for filling a section of a pipe line to be hydrostatically tested, the apparatus comprising:

a rigid body fluid tight except for having at least one opening in a side thereof and one opening in each end thereof;

a pair of ring means mounted adjacent each end of said body on opposite sides of said side opening, said ring means having a diameter substantially equal to that of the pipe line section being tested and having a fluidtight sliding seal therewith; and

one way valve means mounted within said end openings for passing fluid from said pipe line section to the interior of said body.

2. An apparatus as defined in claim 1, and wherein the cross-sectional area of said body is lessthan the cross-sectional area of said ring means, forming thereby a chamber defined by said body exterior, said pipe line section, and between said pair of ring means.

tended through the longitudinal axis of said body, with said ends exposed beyond the ends of said body, said tube having at least one slot formed therein within said body, having a stop member mounted at each exposed end thereof, and including a slide valve slidably mounted within said tube and forming a fluid-tight slidable seal therein, said slide valve engageable with either of said stop members. 

